I went completely backwards. Started with a 43 then bought a 42 and a 642. Haven't found any real reason to carry the 43. I only shoot 147 gn out of the 43 though. I find 147 gn in small guns a lot more pleasant to shoot and shoot quickly.
Glock 42 is much better balanced and I can shoot it quicker, less weight, thinner, rides easier in a pocket.
642 is my pocket ranch gun/ do all. So is my lcr 22 mag.